Periodontal DiseasesNCT07272564
Kynurenine Pathway in Parkinson's Disease
A study testing Saliva and serum sampling and Saliva, serum and GCF sampling in people with Periodontal Diseases and Inflammation, run by Medipol University at 1 site in Turkey (Türkiye).
Trial summary
Parkinson's disease is a slowly progressing disease that affects the motor and non-motor functions of an individual. Periodontitis is an inflammatory chronic disease resulting in the destruction of tooth supporting structures. Inflammation has been identified as an important factor in both diseases. Read more about this study
- Who is it for?
- Ages 18 to 75 yearsHealthy volunteers can take part
- Conditions the study is for
- Periodontal Diseases, Inflammation
- What is being tested?
- Saliva and serum sampling and Saliva, serum and GCF sampling
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 60 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 15 May 2022to 18 Jun 2023
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 75 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- systemically healthy
- clinical diagnosis of periodontitis
- clinical diagnosis of periodontal health
Who cannot join
- history of regular use of systemic antibiotics anti-inflammatory, or antioxidant drugs (previous 3 months)
- nonsurgical periodontal treatment (previous 6 months)
- surgical periodontal treatment (previous 12 months)
- presence of<10 teeth
- current medications affecting gingival health (calcium channel blockers, phenytoin, cyclosporine, and hormone replacement therapy)
- diabetes
Show all 11Show fewer
- diagnosis of rheumatoid arthritis
- pregnancy
- lactating
- smoking
- excessive alcohol consumption.
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Istanbul Medipol University, School of Dentistry
Istanbul, Fatih
About this study
Official title: Periodontal Inflammation and Tryptophan-Kynurenine Metabolism in Parkinson's Disease
Parkinson's disease is a slowly progressing disease that affects the motor and non-motor functions of an individual. Periodontitis is an inflammatory chronic disease resulting in the destruction of tooth supporting structures. Inflammation has been identified as an important factor in both diseases. Given this common mechanism, the question arises as to how they may affect each other when both diseases occur together. In this study, we compared the metabolism of tryptophan, a natural amino acid of the human body, and observed whether such a process provides a biological link between periodontitis and Parkinson's disease. We extracted the saliva and blood samples of patients of Parkinson's disease and periodontitis, patients of periodontitis and healthy human beings. Comparisons between the three were made, and it was found that levels of some metabolites of tryptophan were higher in the patients of both diseases. These findings raise the possibility of a close biological connection between periodontal and brain health. Through an increased understanding of this connection in the future, new approaches for diagnosis and treatment of Parkinson's disease and periodontitis may be developed.
Read the detailed description
Saliva and serum samples were collected from 20 Stage III, Grade B periodontitis patients with PAD (Parkinson+periodontitis group) and without PAD (periodontitis group), and 20 periodontally and systemically healthy (control group). Samples were analyzed for TRP, KYN, KYN/TRP ratio, KYNA, 3OHKYN, picolinic acid (PA), and quinolinic acid (QA) by liquid chromatography-mass spectrometry. Clinical periodontal parameters [plaque index (PI), probing pocket depth (PPD), clinical attachment loss (CAL), and bleeding on probing (BOP)] were recorded.
- Conditions
- Periodontal Diseases, Inflammation
- Being tested
- Saliva and serum sampling, Saliva, serum and GCF sampling
- Keywords
- periodontal disease, Tryptophan, Kynurenine
- Medical subject headings
- Periodontal Diseases, Inflammation
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Saliva and serum samplingOther
Saliva were collected to analyze the selected markers as unstimulated samples during the early hours of the day. The saliva was centrifuged and then transferred into Eppendorf tubes. Venous puncture was performed after saliva collection and 10 mL of blood samples were collected by qualified staff from each participant. Saliva and serum were then stored at -80 °C until analysis.
Saliva, serum and GCF samplingOther
Saliva were collected to analyze the selected markers as unstimulated samples during the early hours of the day. The saliva was centrifuged and then transferred into Eppendorf tubes. Venous puncture was performed after saliva collection and 10 mL of blood samples were collected by qualified staff from each participant. Saliva and serum were then stored at -80 °C until analysis.
| Study group | Role | What they receive |
|---|---|---|
| Active Comparator | Active comparator | Saliva and serum collection of patients and samples molecules analysis Receives: Other: Saliva and serum sampling |
| Experimental | Experimental | Samples were analyzed for TRP, KYN, KYN/TRP ratio, KYNA, 3OHKYN, picolinic acid (PA), and quinolinic acid (QA) by liquid chromatography-mass spectrometry. Clinical periodontal parameters [plaque index (PI), probing pocket depth (PPD), clinical attachment loss (CAL), and bleeding on probing (BOP)] were recorded. Receives: Other: Saliva, serum and GCF sampling |
What is being measured
The primary outcome is the main question the study is designed to answer.
Pocket probing depth
Measurement of the depth of a sulcus or periodontal pocket determined by measuring distance from a gingival margin to the base of the sulcus or pocket with a calibrated periodontal probe.
Measured: 6 months
Clinical attachment level
Clinical attachment level (or loss, CAL) is a more accurate indicator of the periodontal support around a tooth than probing depth alone. CAL is measured from a fixed point on the tooth that does not change, the CEJ.
To calculate CAL, two measurements are needed: distance from the gingival margin to the CEJ and probing depth.
In recession: probing depth (+) gingival margin to the CEJ (add). In tissue overgrowth: probing depth (-) gingival margin to the CEJ (subtract)
Measured: 6 months
Bleeding on probing
referring to bleeding that is induced by gentle manipulation of the tissue at the depth of the gingival sulcus, or interface between the gingiva and a tooth.
Measured: 6 months
Secondary outcomes (1)
Saliva and serum samples processing and analyses
Samples were analyzed for TRP, KYN, KYN/TRP ratio, KYNA, 3OHKYN, picolinic acid (PA), and quinolinic acid (QA) by liquid chromatography-mass spectrometry.
Measured: 1 month
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted9 Dec 2025
- Study start15 May 2022
- Primary completion10 Jan 2023
- Study completion18 Jun 2023
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Periodontal DiseasesStudies of the same condition, open and under way.
- More trials run by Medipol UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Single group
- Model description
- Saliva and serum samples were collected from periodontitis patients and with Parkinson's +periodontitis patients. Samples were analyzed for TRP, KYN, KYN/TRP ratio, KYNA, 3OHKYN, picolinic acid (PA), and quinolinic acid (QA) by liquid chromatography-mass spectrometry.
- Masking
- None (open label)
- Enrolment
- 60 participants (actual)
Sponsor and investigators
- Lead sponsor
- Medipol University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Melis Yilmaz, Medipol University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07272564
- Sponsor's protocol ID
- 1082
- Status last verified
- Nov 2025
- First submitted
- 26 Nov 2025
- Last updated
- 9 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Yilmaz M, Bakici A, Parlat R, Akpinar IN, Karaaslan R, Balci N, Toygar H, Kurgan S, Serdar MA, Kantarci A. Periodontal inflammation and tryptophan-kynurenine metabolism in Parkinson's disease. Clin Oral Investig. 2026 Mar 25;30(4):144. doi: 10.1007/s00784-026-06853-4.
PubMed 41876924
Study at a glance
From the registry record, last updated by the sponsor on 9 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Periodontal Inflammation and Tryptophan-Kynurenine Metabolism in Parkinson's Disease
- ClinicalTrials.gov ID
- NCT07272564
- Acronym / sponsor ID
- 1082
- Conditions
- Periodontal Diseases, Inflammation
- Keywords
- periodontal disease, Tryptophan, Kynurenine
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 60 participants (actual)
- Lead sponsor
- Medipol UniversityUniversity, hospital or other
- Study start
- 15 May 2022 (actual)
- Primary completion
- 10 Jan 2023 (actual)
- Study completion
- 18 Jun 2023 (actual)
- First posted
- 9 Dec 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Parkinson's disease is a slowly progressing disease that affects the motor and non-motor functions of an individual. Periodontitis is an inflammatory chronic disease resulting in the destruction of tooth supporting structures. Inflammation has been identified as an important factor in both diseases. Given this common mechanism, the question arises as to how they may affect each other when both diseases occur together. In this study, we compared the metabolism of tryptophan, a natural amino acid of the human body, and observed whether such a process provides a biological link between periodontitis and Parkinson's disease. We extracted the saliva and blood samples of patients of Parkinson's disease and periodontitis, patients of periodontitis and healthy human beings. Comparisons between the three were made, and it was found that levels of some metabolites of tryptophan were higher in the patients of both diseases. These findings raise the possibility of a close biological connection between periodontal and brain health. Through an increased understanding of this connection in the future, new approaches for diagnosis and treatment of Parkinson's disease and periodontitis may be developed.
Detailed description
Saliva and serum samples were collected from 20 Stage III, Grade B periodontitis patients with PAD (Parkinson+periodontitis group) and without PAD (periodontitis group), and 20 periodontally and systemically healthy (control group). Samples were analyzed for TRP, KYN, KYN/TRP ratio, KYNA, 3OHKYN, picolinic acid (PA), and quinolinic acid (QA) by liquid chromatography-mass spectrometry. Clinical periodontal parameters [plaque index (PI), probing pocket depth (PPD), clinical attachment loss (CAL), and bleeding on probing (BOP)] were recorded.
Study design
- Primary purpose
- Prevention
- Allocation
- Randomised
- Intervention model
- Single group
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- Saliva and serum samples were collected from periodontitis patients and with Parkinson's +periodontitis patients. Samples were analyzed for TRP, KYN, KYN/TRP ratio, KYNA, 3OHKYN, picolinic acid (PA), and quinolinic acid (QA) by liquid chromatography-mass spectrometry.
| Arm | Type | Receives |
|---|---|---|
| Active Comparator | Active comparator | Other: Saliva and serum samplingSaliva and serum collection of patients and samples molecules analysis |
| Experimental | Experimental | Other: Saliva, serum and GCF samplingSamples were analyzed for TRP, KYN, KYN/TRP ratio, KYNA, 3OHKYN, picolinic acid (PA), and quinolinic acid (QA) by liquid chromatography-mass spectrometry. Clinical periodontal parameters [plaque index (PI), probing pocket depth (PPD), clinical attachment loss (CAL), and bleeding on probing (BOP)] were recorded. |
Who may qualify
- Ages
- 18 to 75 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- systemically healthy
Key exclusion criteria (11 listed)
- history of regular use of systemic antibiotics anti-inflammatory, or antioxidant drugs (previous 3 months)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Saliva and serum samplingSaliva were collected to analyze the selected markers as unstimulated samples during the early hours of the day. The saliva was centrifuged and then transferred into Eppendorf tubes. Venous puncture was performed after saliva collection and 10 mL of blood samples were collected by qualified staff from each participant. Saliva and serum were then stored at -80 °C until analysis. | Other | Active Comparator |
| Saliva, serum and GCF samplingSaliva were collected to analyze the selected markers as unstimulated samples during the early hours of the day. The saliva was centrifuged and then transferred into Eppendorf tubes. Venous puncture was performed after saliva collection and 10 mL of blood samples were collected by qualified staff from each participant. Saliva and serum were then stored at -80 °C until analysis. | Other | Experimental |
Primary outcome
Pocket probing depth
Time frame: 6 months
Measurement of the depth of a sulcus or periodontal pocket determined by measuring distance from a gingival margin to the base of the sulcus or pocket with a calibrated periodontal probe.
Clinical attachment level
Time frame: 6 months
Clinical attachment level (or loss, CAL) is a more accurate indicator of the periodontal support around a tooth than probing depth alone. CAL is measured from a fixed point on the tooth that does not change, the CEJ. To calculate CAL, two measurements are needed: distance from the gingival margin to the CEJ and probing depth. In recession: probing depth (+) gingival margin to the CEJ (add). In tissue overgrowth: probing depth (-) gingival margin to the CEJ (subtract)
Bleeding on probing
Time frame: 6 months
referring to bleeding that is induced by gentle manipulation of the tissue at the depth of the gingival sulcus, or interface between the gingiva and a tooth.
1 secondary outcome
Saliva and serum samples processing and analyses
Time frame: 1 month
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 9 Dec 2025.
- Derived from this study: PubMed 41876924Yilmaz M, Bakici A, Parlat R, Akpinar IN, Karaaslan R, Balci N, Toygar H, Kurgan S, Serdar MA, Kantarci A. Periodontal inflammation and tryptophan-kynurenine metabolism in Parkinson's disease. Clin Oral Investig. 2026 Mar 25;30(4):144. doi: 10.1007/s00784-026-06853-4.
- Individual participant dataSharing planned: No
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
The record lists no contact. Use the official record to reach the sponsor.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Saliva and serum sampling and Saliva, serum and GCF sampling in people with Periodontal Diseases and Inflammation, run by Medipol University at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 9 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Pocket probing depth (time frame: 6 months). The study lists 3 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07272564, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 9 Dec 2025.